A color cathode-ray tube (CRT) includes an electron gun for generating and directing three electron beams to a screen of the tube. The screen is located on the inner surface of a cylindrical faceplate of the tube and is made up of an array of elements of three different color emitting phosphors. An apertured mask, such as a tension mask, is interposed between the gun and the screen to permit each electron beam to strike only the phosphor elements associated with that beam. A tension mask is a thin sheet of metal, such as steel, that is contoured to somewhat parallel the inner surface of the cylindrical faceplate of the tube. The tension mask generally comprises parallel strands of wire attached to a relatively massive support frame which maintains tension on the strands. Another type of CRT has a tensioned focus mask comprising dual sets of conductive strands that are perpendicular to each other and usually separated by an insulative layer.
In either type of CRT it is necessary that the strands of the tension mask are attached to the support frame, and that the tension be maintained during operation of the tube. A drawback of prior support frames is that during the thermal processing cycle, in which the faceplate panel is sealed to the funnel of the tube, the sealing temperature, which is in the range of about 440-460.degree. C., causes a permanent elongation, or "creep" of the mask strands which lowers the tension in the strands during normal tube operation. High strand tension during operation is desirable for good microphonic performance and to absorb the thermal expansion of the strands due to heating by the electron beam during normal operation. The heating during normal operation generally raises the temperature of the tension mask to less than about 65.degree. C.
U.S. Pat. No. 5,594,300, issued to Nosker et al., on Jan. 14, 1997, describes a CRT having a tension mask and compliant support frame assembly. The support frame members include two portions that parallel the major axis of the CRT and two portions that parallel the minor axis. Each portion that parallels the major axis includes a rigid section and a compliant section that is cantilevered from the rigid section. The cantilevered sections maintain the tension on the mask strands. Although such a structure is an improvement over more massive frame structures and reduces the weight and cost of the frame assembly, there is still a need for further improvement in CRT types having a cylindrical faceplate, to improve the performance of the frame assembly during all phases of tube processing and operation.